a. Bounded by two trend lines; the lower is horizontal and the upper slopes downward.
b. Prices can break in either direction but most commonly downward.
One of the oddest features of the Labour tax row is how raising allowances, which the media allowed the LDs to describe as progressive (in spite of evidence to contrary) through the coalition years, is now seen by everyone as very right wing
— Tom Clark (@prospect_clark) November 2, 2018